1. Technical Field
The invention relates to a pedal of bicycle, particularly to a step-in or clipless pedal.
2. Related Art
In recently years, bicycling becomes a worldwide popular form of recreation, sport and transportation. Depending upon different purposes of bicycling, there are many kinds of bicycles, such as road bikes, mountain bikes, folding bikes, etc. Whether bicycles are used for recreation, transportation or competition, the bicycle industry always keeps improving all components bicycle. An important component of a bicycle, especially for road bikes, is the step-in pedal, as known as clipless pedal.
The step-in or clipless pedal releasably engages with a cleat fastened under a sole of a cyclist's shoe. The clipless pedal has a spindle that can be screwed on a crank arm, a pedal body which is rotatably mounted on this spindle, and a cleat engagement mechanism on the pedal body. In a road bike, a racing clipless pedal typically has a cleat engagement mechanism on one side of the pedal body. A rider steps onto the pedal and the cleat engagement mechanism automatically grips the cleat to the sole of the rider's shoe.
More specifically, when attaching the cyclist's shoe to the step-in pedal via the cleat, the cyclist moves the shoe obliquely downwardly and forwardly relative to the pedal body such that the front end of the cleat engages a front hook or clamping member of the pedal body. Once the front end of the cleat is engaged with the front hook of the pedal body, the cyclist places the rear end of the cleat in contact with a guide portion of the rear hook or clamping member of the pedal body. In this position, the cyclist presses the shoe downwardly against the pedal to cause the rear hook or clamping member to initially pivot rearwardly against the force of a spring to move the rear hook or clamping member to a cleat releasing position. The rear end of the cleat then enters a position opposite a back face of the rear hook or clamping member. Then, the rear hook or clamping member returns under the force of a biasing member or spring so that the rear hook or clamping member engages the rear end of the cleat. This engagement fixes the cyclist's shoe to the pedal via the cleat.
Although the engagement of the pedal and cleat appears secure, in fact it is not secure enough because there are only two engagement points at the front end and rear end and the cleat still can horizontally rotate relative to the pedal. On the other hand, conventional cleats and pedals are made of rigid material, so there must be gaps between them. These gaps may also cause the engagement of the cleat and pedal to be unstable.